Pharmaceuticals are mainly introduced into the environment via two pathways. The first path is the applications of veterinary drugs to animals, as they are excreted, high concentration are found in manure. As this contaminated manure is utilised for fertilising the fields a soil issue arises. The second path is the treatment of infections in the human medicine. When these residues are excreted they are transported through the sewers to sewage treatment plants and are then discharged with the treated wastewater into the aquatic environment. In this book the environmental fate of the antibiotics erythromycin, roxithromycin, clarithromycin, tylosin, oleandomycin, tiamulin, salinomycin, the steroid hormones 1estradiol, estrone, estriol, hydroxyestrone and estradiol-17-acetate, the hormone-conjugates estradiol 3-sulfate and estrone 3-sulfate, the oral contraceptives ethinylestradiol and mestranol were studied.